One is not righteous who does much, but the one who, without work, believes much in Christ. The law says, 'Do this,' and it is never done. Grace says, 'Believe in this,' and everything is already done.
Martin LutherWhilst a man is persuaded that he has it in his power to contribute anything, be it ever so little, to his salvation, he remains in carnal self-confidence; he is not a self-despairer, and therefore is not duly humbled before God, he believes he may lend a helping hand in his salvation, but on the contrary, whoever is truly convinced that the whole work depends singly on the will of God, such a person renounces his own will and strength; he waits and prays for the operation of God, nor waits and prays in vain
Martin LutherThe Devil can so completely assume the human form, when he wants to deceive us, that we may well lie with what seems to be a woman, of real flesh and blood, and yet all the while 'tis only the Devil in the shape of a woman. 'Tis the same with women, who may think that a man is in bed with them, yet 'tis only the Devil; and...the result of this connection is oftentimes an imp of darkness, half mortal, half devil.
Martin LutherWhen I am assailed with heavy tribulations, I rush out among my pigs rather than remain alone by myself. The human heart is like a millstone in a mill: when you put wheat under it, it turns and grinds and bruises the wheat to flour; if you put no wheat, it still grinds on, but then 'tis itself it grinds and wears away. So the human heart, unless it be occupied with some employment, leaves space for the devil, who wriggles himself in and brings with him a whole host of evil thoughts, temptations, and tribulations, which grind out the heart.
Martin Luther